A server may have multiple processor sockets coupled together. Each processor may have multiple cores. When all cores in a processor (in a socket) enter C3 or C6 power saving states, the socket is considered to be in a PC2 power state, where the power states are defined by the Advanced Configuration and Power Interface (ACPI) specification. The server enters PC3 or PC6 power states, when all cores of all processors in all sockets of the server are in C3 or C6 power states, respectively.
However, in PC2 power state, a significant portion of the processor remains active and powered up because other cores of other processors in other sockets (of the server) may not be in C3 or C6 power saving states. One reason for part of the processor to remain in active state during PC2 socket power state is because any operating core from any other processor of another socket may request use of resources of the processor. Keeping part of the processor in an active state during PC2 socket power state consumes dynamic power.